W3bbo wrote:﻿Hypothetically speaking, how hard would it be to add another "Calendar Provider" for .NET which implements
the 28-hour day?

It supports Gregorian, Jewish, and the Moon/Islamic calendar... how 'bout for futurists trying to differentiate themselves as being special?

Technically speaking, one day is 23 hours, 56 minutes, 2 seconds, ~400ms. Why not go with this technically-correct number instead? It even eliminates the necessity for leap day.

Apparently, that's not entirely true. As far as I understand it, it takes 23 hours and 56 minutes for the earth to rotate to where the sun -was- last day, but the sun will have moved, so it takes the earth 4 minutes to catch up. Meaning that our relative position
to the sun is the same after the full 24 hours.

﻿You're assuming the leap year is enough every four years. It's not. There are leap seconds as well in the system, it's not as clear cut as 1 24 hour period every 4 years.

I heard it's (and I take a deep breath)

28 days in februaryexcept every fourth year when it's 29except when that fourth year coincides with a centuary (when it's 28)except if that centuary is itself a multiple of four centuaries (when it's 29)except if that centuary is also a millenum (e.g. 2000 had 28 days in feb)except if that millenium is a four-millenium (e.g. 4000 will have 29 days).

While one might be tempted to extrapolate up, the length of time means that the Earth's orbit (which decays slightly each year) actually causes it to go out of sync, so you can't extrapolate - in 2000 years time if anyone's still around, they'll be going by
UNIX timestamps anyway.

There have been three "leap seconds" in the past centuary. The first was erroneously inserted due to a syncronisation issue with the atomic clocks. The second leap second (there's a mouthful) was because of the Earth's decaying orbit and the third one was to
correct the error of the first. A leap second "ought" to be inserted in the region of once every centuary.

For the purposes of science, a day (1d) is defined as 86,400 seconds exactly, using the SI definition of second (9,192,631,770 periods of the radiation emitted by the decay of two hyperfine levels of the ground state of a caesium-133 atom). This is an
exact defintion, but doesn't correspond to the actual period of rotation of a point on the Earth's surface with respect to it's centre (of volume). This period of time (86,400s) is also known as a "civil day", perhaps as an attempt to keep the peace.

But when it all comes down to it all, most people define a day as the period of time between when they wake up, and when they arrive back at their flat approximately 18 hours later, which brings me to my ultimate point. Noone cares.

﻿28 days in februaryexcept every fourth year when it's 29except when that fourth year coincides with a centuary (when it's 28)except if that centuary is itself a multiple of four centuaries (when it's 29)except if that centuary is also a millenum (e.g. 2000 had 28 days in feb)except if that millenium is a four-millenium (e.g. 4000 will have 29 days).

Sorry, but those last two rules are nonsense. 2000 was a leap-year, it had 29 days in February (check with any calendar if you like). The first three rules are sufficient.

As for W3bbo's question, it's not impossible, but rather difficult, as .Net's Calendar class is based rather strongly about regular earth calendars.

You would at least have to override AddDays to add 28 hours instead of 24. And AddWeeks to add 6 days. Then you'd have to invent a month system so that there's a whole number of days in each month and a whole number of months in each year and override GetDaysInMonth
and GetDaysInYear and GetMonthsInYear appropriately.

﻿By then, time will need to be based on something a bit more regular and atronomical. Plus, given that both gravity and speed affect time, we'll need some kind of outside reference.

Remember, Time is relative...it always seems to go slower when you are around your extended family.

Since time isn't an absolute, I guess any real time system would have two meters. "Local time" for time in your locality in spacetime, and "UTC time", the date/time currently on Earth, taken as the "base" time.

But this would only reliably work if you can accurately measure your velocity relative to Earth.

﻿Since time isn't an absolute, I guess any real time system would have two meters. "Local time" for time in your locality in spacetime, and "UTC time", the date/time currently on Earth, taken as the "base" time.

Like the clocks they used for determing longitude - one set to GMT the other to local time?